Driveshaft

[delroy]

I've seen several youtube videos about a one piece driveshaft versus the original two piece with hanger bearing. I'm skeptical, although the one piece is for sure lighter and simpler. But Ford must have had good reasons for using an expensive and more complicated solution. What do you guys think?
I recently removed my D/S on my 2014 GT. Not a fun job on the floor, but not too bad. I reinstalled the original back in the car after inspecting it. One downside of a one piece D/S is that it's easily dented or bent during maintenance of something else. The original D/S in my case had a sticker on it saying that if it's dropped it's scrap. Severe!

 

[GriffX]

Don't know but most of the cars have 2-piece DS, I guess it has to do with comfort, damping vibrations is easier?
With a one piece, the full length DS moves with rear suspension (on our cars) and engine movement.

On my OEM DS, I have a broad vibration band from 60-75 MPH, not really annoying but noticeable. I measured the angle between transmission and 1st part DS to 2.7 deg. Not sure if this is ok. The center support has the aluminum spacers installed (build 07).

 

[UpAllNight91]

I tried both a Ford racing driveshaft and a DSS driveshaft. The DSS had a bad vibe under heavy torque and DSS blamed it on my lowered car (BMR sport springs). Claiming the driveshaft was too long for my lowered car. Wanted to upcharge me for a custom shaft. I sent back for a refund. The Ford racing does ok but under WOT at higher RPMs there is a mild harshness or NVH that the car does not have with the stock 2 peice (tried every pinion angle possible with the adjustable uppercontrol arm). But otherwise is perfectly smooth. The Ford racing might require a adjustment upper control arm (which i was using with the Ford racing shaft) on your car depending where your pinion angle is at currently but these control arms are sure to bring in some NVH so expect that. In the end I ended up putting a good used stock driveshaft in and my stock upper Control arm back on. If you care about NVH the stock stuff seems to be the only option. As for the vibrations that the stock shaft can bring at around 70 MPH, this is from the center support. If the rubber dampener for the center bearing support is loose and sloppy from age and rot it will bring a mild vibration at highway speeds and also during lower RPM heavy torque like 6th gear around 50 MPH. The cure for that is to get a good used shaft with a good tight center support, or buy the aftermarket one that replaces the stock one for about 350 bucks. Or modify the stock one to tighten it back up. There is a guy in another forum who made a thread showing exactly how to do that.

 

[UpAllNight91]

 

[crjackson]

damping vibrations is easier?

This!

There is a guy in another forum who made a thread showing exactly how to do that.

You’re probably talking about OX1’s thread.

https://www.allfordmustangs.com/threads/driveshaft-carrier-bearing-replacement.1105017/?post_id=9332623#:~:text=So%20As%20mentioned%2C%20I%20marked%20all%20three%20%22joints%22%20with%20paint%20before%20removing.

 

[UpAllNight91]

Yes sir. Thanks for finding the link

 

[Miker]

I have the FRPP in my 2005. My car is not lowered. I think the problem with the one piece is when peoples cars are lowered. On mine the outcome was perfection. It made the car seem more connected to the throttle in a seamless way if that makes any sense. I have no vibration or noise from the shaft but it does amplify any clunk from a lazy shift. It's a big resonator in that way. I wouldn't give denting it a second thought.

 

[GriffX]

You’re probably talking about @OX1’s thread.

One hint, I did this and used sh 70 NBR/SBR rubber, it was way too stiff, DS perfectly quiet at 70, but lots of NVH at high torque low speed. Then I filled the holes with the NBR/SBR rubber instead of surrounding and I'm in an in-between state. Quiet at low speed and broad increase in NVH from 60-75. Must find softer rubber somewhere.

 

[GriffX]

It made the car seem more connected to the throttle in a seamless way if that makes any sense.

Yes, with my stiff modification, I could spin the wheels much easier. It looks like torque peaks get lost in the rubber bushing.

 

[JC SSP]

Less rotation mass equals more HP/TQ being put to the rear wheels. Simple physics…

 

[crjackson]

I just replaced mine about 1-2 months ago. I went with the FRPP 1-Piece aluminum, and I’m happy with it. It did increase NVH (slightly) at very low RPM’S. It seems acceptable to me. I haven’t taken any long trips yet, so I can’t really say how that will fair.

 

[UpAllNight91]

The vibration or harness or whatever that i was getting with the Ford racing shaft seems to only happen at the higher end of the RPMS and at the peak of my cars power (2013 Mustang GT full bolt on NA car, long tubes, 2018 intake and all that mess). Honestly if the car was making just 30 less HP it probably would never make the NVH. But at the peak it seems to just barely cross that threshold where there is a resonance that comes in. I tried it with both the stock UCA and also a adjustable UCA and same results. I tried different pinion angles as well. I still have the Ford racing shaft and adjustable UCA in my garage. Not sure if I will try it out again one day but for now the stock driveshaft and stock UCA are in the car and its good. Also the adjustable UCA with poly bushing brings in even more NVH from the diff. I have a Detroit true track diff and they are known to be a little clunky with more lash than stock. With the stock UCA its livable but with the adjustable UCA that has poly bushings it brings too much diff noise into the cab for a daily driver IMO.
With my experience with the DSS shaft that has a CV on the diff side that is also telescopic (slides in and out) there is a working range in and out of only about little less than a inch before the CV either bottoms out or is pulled out and apart. This is too close for comfort for me. Mine was bottoming out under heavy torque and they said it was because the car was lowered. My argument is it should never bottom out or be pulled apart throughout the full stroke of the rear ends suspension otherwise a issue is bound to show up at some point. So I returned it. Now that I'm familiar with it I don't know if I could ever fully trust a driveshaft that has a telescopic working range of less than a inch before something bad happens. Not on a daily driver at least. When a driveshaft fails it can damage all kinds of stuff. Its just not worth the risk for a daily driver in my opinion. I do trust the Ford racing driveshaft though. If it just didn't have that NVH at peak output it would be in my car right now

 

[nyuk98GT]

Don't know but most of the cars have 2-piece DS, I guess it has to do with comfort, damping vibrations is easier?
With a one piece, the full length DS moves with rear suspension (on our cars) and engine movement.

On my OEM DS, I have a broad vibration band from 60-75 MPH, not really annoying but noticeable. I measured the angle between transmission and 1st part DS to 2.7 deg. Not sure if this is ok. The center support has the aluminum spacers installed (build 07).

GriffX,

Did you find any yellow paint on the driveshaft to match the paint on the pinion flange? If the paint is not matched then it probably needs some easy (but time-consuming) adjustment.

The adjustment is rotating the driveshaft 90 degrees clockwise or counter-clockwise to the pinion flange. If things improve, leave things as they are. If no improvement, try another 90 degrees and repeat once more if the second trial doesn't improve things. If no improvement then the shaft probably needs (re-)balancing.

HTH,

Chris

 

[GriffX]

Did you find any yellow paint on the driveshaft to match the paint on the pinion flange? If the paint is not matched then it probably needs some easy (but time-consuming) adjustment.

That's what I thought first. I have blue dots at the pinion flange and the CV joint in the rear and orange dots at the transmission and U-joint. I'm the first owner of the car and had a sharp and loud resonance around 109-112 kmh (67-69 mph). Speed limits are usually 62 and 74 mph. I noticed that this rubber in the support bracket is very loose (could push the shaft up 2/3 inch with no resistance) and tried to modify it according to that advice above.



1st modification, rubber band fully around: No play at all, no noise at highway speed, wheels brake loose very easy, but rumble at low speed, high torque -> doesn't sound right

2nd mod: Instead of full rubber band around I filled the outer spaces with rubber pieces. I can move the shaft with my hand 1/8 inch, no rumble at low speed but broad resonance at highway speed, not as loud as OEM state.

3rd mod (next winter): Will try to find softer silicone rubber and fill the spaces with it.

As you mentioned, even balancing is a very time consuming process.

 

[nyuk98GT]

GriffX,

JXB Performance's driveshaft carrier looks pretty nice and is available with street or track (or both) rubber inserts. Cost is about $300 but should eliminate the vibration issue. They may give you some free tech advice if you give them a call and tell them about your work - kind of like professional courtesy .

Interested to hear about the update(s).

Chris

/edit/
That rubber looks pretty tired (no offense). I think the rubber is twisting and sliding on itself creating areas of thicker and thinner rubber, just enough to cause vibration.
/end of edit/

 

[GriffX]

GriffX,

JXB Performance's driveshaft carrier looks pretty nice and is available with street or track (or both) rubber inserts. Cost is about $300 but should eliminate the vibration issue. They may give you some free tech advice if you give them a call and tell them about your work - kind of like professional courtesy .

Interested to hear about the update(s).

Chris

/edit/
That rubber looks pretty tired (no offense). I think the rubber is twisting and sliding on itself creating areas of thicker and thinner rubber, just enough to cause vibration.
/end of edit/

Totally agree. The JXB looks really nice, I guess it is around 400€ here in Germany. But, I noticed yesterday that the upper part of this metal bracket is bend differently and not clamping the rubber down on my driveshaft. Maybe I just got an production error? (And that my driveshaft was painted black from factory)



Right now my 25 year old Mercedes occupies my lift and my Mustang is dayli driver, will take some time before I can do something.

 

[kazman59]

I hear a lot on negative comments about one piece driveshafts. Mostly DSS and some FRPP. Rarely hear any about the Ford carbon fiber. I have an '07 GT500 - FRPP M-FR3A-MSVTA SUSPENSION, M-5649-R1 LCA, (lowered) - 2014 GT500 carbon fiber drive shaft with adapter. No issues whatsoever.

 

[pass1over]

I've been running a 1 piece DSS aluminum shaft in my car for almost 12 years now with no vibration issues or anything. My car is super super low and it doesn't rub on anything. Zero complaints with that mod.

 

[UpAllNight91]

I've been running a 1 piece DSS aluminum shaft in my car for almost 12 years now with no vibration issues or anything. My car is super super low and it doesn't rub on anything. Zero complaints with that mod.

I was hoping to get lucky like you with the DSS and I heard of others with lowered cars running the DSS with no issues. Thats why I tried it.. I honestly think they cut the shaft length wrong and didn't want to admit it and take ownership of the fault. It wasn't rubbing anything on the car, but the CV was bottoming out internally causing a nasty bind during heavy torque (when I removed the shaft I could see the witness mark on the very rear of the shaft where the CV was being pressed on the CV's back plate and bottoming out) . The customer service over the phone sucked badly. They kept thinking I had a S550 no matter how many times I told them it was a 2013. And it would often take over a day to get a return call from them on the issue. Between the bad customer service and learning the CV has a very very limited telescopic range I won't use DSS again. I was hoping i got lucky like you and was hoping for the best. I do know they have changed some things since 12 years ago. No adaptor plate needed anymore and such so who knows

 

[pass1over]

Mine was a little too short I think. I ended up needing the extra spacer to take up a little bit of the distance. The measurement they have you take, mine was on the very outer limit, which I wasn't comfortable with. I didn't have any vibrations, but I didn't like it.

It's been so long since I had to deal with them, I don't remember what their customer service was like. I had it rebuilt like 9 years ago or so, so it's been awhile.